2,185 research outputs found
Tailoring Gold Nanoparticle Characteristics and the Impact on Aqueous-Phase Oxidation of Glycerol
Poly(vinyl alcohol) (PVA)-stabilized Au nanoparticles (NPs) were synthesized by colloidal methods in which temperature variations (â75 to 75 °C) and mixed H2O/EtOH solvent ratios (0, 50, and 100 vol/vol) were used. The resulting Au NPs were immobilized on TiO2 (P25), and their catalytic performance was investigated for the liquid phase oxidation of glycerol. For each unique solvent system, there was a systematic increase in the average Au particle diameter as the temperature of the colloidal preparation increased. Generation of the Au NPs in H2O at 1 °C resulted in a high observed activity compared with current Au/TiO2 catalysts (turnover frequency = 915 hâ1). Interestingly, Au catalysts with similar average particle sizes but prepared under different conditions had contrasting catalytic performance. For the most active catalyst, aberration-corrected high angle annular dark field scanning transmission electron microscopy analysis identified the presence of isolated Au clusters (from 1 to 5 atoms) for the first time using a modified colloidal method, which was supported by experimental and computational CO adsorption studies. It is proposed that the variations in the populations of these species, in combination with other solvent/PVA effects, is responsible for the contrasting catalytic properties
Childrenâs Environmental Health Faculty Champions Initiative: A Successful Model for Integrating Environmental Health into Pediatric Health Care
BackgroundPediatric medical and nursing education lack the environmental health content needed to properly prepare health care professionals to prevent, recognize, manage, and treat environmental exposureârelated diseases. The need for improvements in health care professionalsâ environmental health knowledge has been expressed by leading institutions. However, few studies have evaluated the effectiveness of programs that incorporate pediatric environmental health (PEH) into curricula and practice.ObjectiveWe evaluated the effectiveness of the National Environmental Education Foundationâs (NEEF) Childrenâs Environmental Health Faculty Champions Initiative, which is designed to build environmental health capacity among pediatric health care professionals.MethodsTwenty-eight pediatric health care professionals participated in a train-the-trainer workshop, in which they were educated to train other health care professionals in PEH and integrate identified PEH competencies into medical and nursing practice and curricula. We evaluated the program using a workshop evaluation tool, action plan, pre- and posttests, baseline and progress assessments, and telephone interviews.ResultsDuring the 12 months following the workshop, the faculty championsâ average pretest score of 52% was significantly elevated (p < 0.0001) to 65.5% on the first posttest and to 71.5% on the second posttest, showing an increase and retention of environmental health knowledge. Faculty champions trained 1,559 health care professionals in PEH, exceeding the goal of 280 health care professionals trained. Ninety percent of faculty champions reported that PEH had been integrated into the curricula at their institution.ConclusionThe initiative was highly effective in achieving its goal of building environmental health capacity among health care professionals. The faculty champions model is a successful method and can be replicated in other arenas
Erratum to: Surface layer proteins from virulent Clostridium difficile ribotypes exhibit signatures of positive selection with consequences for innate immune response
âUpon publication of the original article [1], it was noticed that there was an error in the author name. The authorâs name should be "MicheĂĄl Mac AogĂĄin" instead of MicheĂĄl MacAogain.
E-cadherin and cell adhesion: a role in architecture and function in the pancreatic islet
Background/Aims: The efficient secretion of insulin from beta-cells requires extensive intra-islet communication. The cell surface adhesion protein epithelial (E)-cadherin (ECAD) establishes and maintains epithelial tissues such as the islets of Langerhans. In this study, the role of ECAD in regulating insulin secretion from pseudoislets was investigated. Methods: The effect of an immuno-neutralising ECAD on gross morphology, cytosolic calcium signalling, direct cell-to-cell communication and insulin secretion was assessed by fura-2 microfluorimetry, Lucifer Yellow dye injection and insulin ELISA in an insulin-secreting model system. Results: Antibody blockade of ECAD reduces glucose-evoked changes in [Ca2+](i) and insulin secretion. Neutralisation of ECAD causes a breakdown in the glucose-stimulated synchronicity of calcium oscillations between discrete regions within the pseudoislet, and the transfer of dye from an individual cell within a cell cluster is attenuated in the absence of ECAD ligation, demonstrating that gap junction communication is disrupted. The functional consequence of neutralising ECAD is a significant reduction in insulin secretion. Conclusion: Cell adhesion via ECAD has distinct roles in the regulation of intercellular communication between beta-cells within islets, with potential repercussions for insulin secretion. Copyright (C) 2007 S. Karger AG, Basel
Andy's Algorithms: new automated digital image analysis pipelines for FIJI.
Quantification of cellular antigens and their interactions via antibody-based detection methods are widely used in scientific research. Accurate high-throughput quantitation of these assays using general image analysis software can be time consuming and challenging, particularly when attempted by users with limited image processing and analysis knowledge. To overcome this, we have designed Andy's Algorithms, a series of automated image analysis pipelines for FIJI, that permits rapid, accurate and reproducible batch-processing of 3,3'-diaminobenzidine (DAB) immunohistochemistry, proximity ligation assays (PLAs) and other common assays. Andy's Algorithms incorporates a step-by-step tutorial and optimization pipeline to make batch image analysis simple for the untrained user and adaptable across laboratories. Andy's algorithms provide a simpler, faster, standardized work flow compared to existing programs, while offering equivalent performance and additional features, in a free to use open-source application of FIJI. Andy's Algorithms are available at GitHub, publicly accessed at https://github.com/andlaw1841/Andy-s-Algorithm
Arduous implementation: Does the Normalisation Process Model explain why it's so difficult to embed decision support technologies for patients in routine clinical practice
Background: decision support technologies (DSTs, also known as decision aids) help patients and professionals take part in collaborative decision-making processes. Trials have shown favorable impacts on patient knowledge, satisfaction, decisional conflict and confidence. However, they have not become routinely embedded in health care settings. Few studies have approached this issue using a theoretical framework. We explained problems of implementing DSTs using the Normalization Process Model, a conceptual model that focuses attention on how complex interventions become routinely embedded in practice.Methods: the Normalization Process Model was used as the basis of conceptual analysis of the outcomes of previous primary research and reviews. Using a virtual working environment we applied the model and its main concepts to examine: the 'workability' of DSTs in professional-patient interactions; how DSTs affect knowledge relations between their users; how DSTs impact on users' skills and performance; and the impact of DSTs on the allocation of organizational resources.Results: conceptual analysis using the Normalization Process Model provided insight on implementation problems for DSTs in routine settings. Current research focuses mainly on the interactional workability of these technologies, but factors related to divisions of labor and health care, and the organizational contexts in which DSTs are used, are poorly described and understood.Conclusion: the model successfully provided a framework for helping to identify factors that promote and inhibit the implementation of DSTs in healthcare and gave us insights into factors influencing the introduction of new technologies into contexts where negotiations are characterized by asymmetries of power and knowledge. Future research and development on the deployment of DSTs needs to take a more holistic approach and give emphasis to the structural conditions and social norms in which these technologies are enacte
Development and preliminary evaluation of EMPOWER for surrogate decision-makers of critically ill patients
OBJECTIVE: The objectives of this study were to develop and refine EMPOWER (Enhancing and Mobilizing the POtential for Wellness and Resilience), a brief manualized cognitive-behavioral, acceptance-based intervention for surrogate decision-makers of critically ill patients and to evaluate its preliminary feasibility, acceptability, and promise in improving surrogates' mental health and patient outcomes. METHOD: Part 1 involved obtaining qualitative stakeholder feedback from 5 bereaved surrogates and 10 critical care and mental health clinicians. Stakeholders were provided with the manual and prompted for feedback on its content, format, and language. Feedback was organized and incorporated into the manual, which was then re-circulated until consensus. In Part 2, surrogates of critically ill patients admitted to an intensive care unit (ICU) reporting moderate anxiety or close attachment were enrolled in an open trial of EMPOWER. Surrogates completed six, 15-20 min modules, totaling 1.5-2 h. Surrogates were administered measures of peritraumatic distress, experiential avoidance, prolonged grief, distress tolerance, anxiety, and depression at pre-intervention, post-intervention, and at 1-month and 3-month follow-up assessments. RESULTS: Part 1 resulted in changes to the EMPOWER manual, including reducing jargon, improving navigability, making EMPOWER applicable for a range of illness scenarios, rearranging the modules, and adding further instructions and psychoeducation. Part 2 findings suggested that EMPOWER is feasible, with 100% of participants completing all modules. The acceptability of EMPOWER appeared strong, with high ratings of effectiveness and helpfulness (M = 8/10). Results showed immediate post-intervention improvements in anxiety (d = -0.41), peritraumatic distress (d = -0.24), and experiential avoidance (d = -0.23). At the 3-month follow-up assessments, surrogates exhibited improvements in prolonged grief symptoms (d = -0.94), depression (d = -0.23), anxiety (d = -0.29), and experiential avoidance (d = -0.30). SIGNIFICANCE OF RESULTS: Preliminary data suggest that EMPOWER is feasible, acceptable, and associated with notable improvements in psychological symptoms among surrogates. Future research should examine EMPOWER with a larger sample in a randomized controlled trial
Thiolated chitosan nanoparticles enhance anti-inflammatory effects of intranasally delivered theophylline
BACKGROUND: Chitosan, a polymer derived from chitin, has been used for nasal drug delivery because of its biocompatibility, biodegradability and bioadhesiveness. Theophylline is a drug that reduces the inflammatory effects of allergic asthma but is difficult to administer at an appropriate dosage without causing adverse side effects. It was hypothesized that adsorption of theophylline to chitosan nanoparticles modified by the addition of thiol groups would improve theophylline absorption by the bronchial epithelium and enhance its anti-inflammatory effects. OBJECTIVES: We sought to develop an improved drug-delivery matrix for theophylline based on thiolated chitosan, and to investigate whether thiolated chitosan nanoparticles (TCNs) can enhance theophylline's capacity to alleviate allergic asthma. METHODS: A mouse model of allergic asthma was used to test the effects of theophylline in vivo. BALB/c mice were sensitized to ovalbumin (OVA) and OVA-challenged to produce an inflammatory allergic condition. They were then treated intranasally with theophylline alone, chitosan nanoparticles alone or theophylline adsorbed to TCNs. The effects of theophylline on cellular infiltration in bronchoalveolar lavage (BAL) fluid, histopathology of lung sections, and apoptosis of lung cells were investigated to determine the effectiveness of TCNs as a drug-delivery vehicle for theophylline. RESULTS: Theophylline alone exerts a moderate anti-inflammatory effect, as evidenced by the decrease in eosinophils in BAL fluid, the reduction of bronchial damage, inhibition of mucus hypersecretion and increased apoptosis of lung cells. The effects of theophylline were significantly enhanced when the drug was delivered by TCNs. CONCLUSION: Intranasal delivery of theophylline complexed with TCNs augmented the anti-inflammatory effects of the drug compared to theophylline administered alone in a mouse model of allergic asthma. The beneficial effects of theophylline in treating asthma may be enhanced through the use of this novel drug delivery system
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